Payment instruments are an essential part of modern payment systems and may include payment cards, credit cards, direct debit cards, and checks, which all relate to non-cash instruments with which end-users of payment systems may transfer funds between accounts and banks or other financial institutions. Most individuals are now issued a vast array of plastic cards by their bank, credit card provider, frequent flyer program provider, customer bonus program provider, car park provider, employer, gym, library, etc. Carrying such a large quantity of cards in a wallet is very inconvenient for users.
Approaches have been variously discussed, where a single card may represent a plurality of issued cards to reduce the actual number of cards. However, since safety and efficiency of payment instruments are important for both maintaining confidence in the currency and keeping the economy running smoothly, each issuer typically relies on its own security standards, which cannot be incorporated into a single card using prior techniques.